ATOMS

SUB ATOMIC PARTICLES

• Particles that are smaller than the atom.
• Small particles composing of nucleons and atoms.
• 3 main sub atomic particles that make up the atom are the Protons, Neutrons and Electrons.

Eugene Goldstein.

PROTONS

• Positively charges sub atomic particles.
• The existence of protons was first discovered by Eugene Goldstein in 1886.
• He observed a cathode ray tube and found rays traveling in the direction opposite to that of the cathode rays. He called those canal rays and concluded that they were composed of positive particles. He called those canal rays and concluded that they were composed of positive particles. 
•   Each proton has a mass about 1840 times that of an electron.

Model of the Canal Rays Goldstein observed.

ELECTRONS

•  Negatively charged subatomic particles.
• Discovered by J. J Thomson in 1897.
•   Thomson performed experiments wherein high voltage electricity was applied across electrically charged plates in a cathode ray tube containing a very small amount of gas, a ray coming from the negatively charged electrode, the cathode was observed.

Cathode Rays observed by J.J Thomson

NEUTRONS

James Chadwick

• Neutrons are sub atomic particles with no charge but with a mass nearly equal to the proton's.
• Sir James Chadwick confirmed the discovery of another atomic particle’s existence: the Neutron.

NOTE:

ü  All atoms are made up of subatomic particles protons, neutrons and electron.

ü  The electronic charge is measured in coulombs (C).

ATOMIC NUMBER (Z)

• Indicates the number of protons and defines the element.

Example: 

<--- Gold's Atomic Number is 79. It has 79 protons and electrons and is also the 79th element in the periodic table :D

ATOMIC MASS (A)

•        The average mass of an atom of an element.

 Gold's Atomic Mass is 197 :D (Remember to round off decimals)---->

A.Z.P.E.N

•          AZPEN stands for Atomic Mass(A), Atomic Number(Z), Proton(P), Electron(E), 
  Neutron (N)
  
  
  Example:
  
  

* A chart that makes us see a more organized data for each element.

IONS

•          Atoms or groups with a positive or negative charge.
•          Formed when electrons are removed or added to a neutral atom, a charged particle of the same element is formed.
•          An ion with a positive charge is called a cation.

•         An ion with a negative charge is called an anion.

ISOTOPES

• Atoms that have the same number of protons and electrons but they each have different number of neutrons.
•            Atoms that have the same number of protons but different numbers of neutron.

Example:

Isotopes of Magnesium

Lithium-6

Lithium-7

Lithium- 8

Submitted By: Group 5

Mia San Juan

Alex Vergara

Cierra Mortega

Jhoanne Sanchez

Elma Tejada